1. Incorporation by Reference
Applicant(s) hereby incorporate herein by reference, any and all U.S. patents, U.S. patent applications, and other documents and printed matter cited or referred to in this application.
2. Field of the Invention
This invention relates generally to safety valves for fuel tanks and more particularly to such a safety valve capable of venting fluids under normal conditions of temperature change, preventing liquid fuel splashes from exiting the fuel tank during rough riding and for preventing fuel leakage should the fuel tank become inverted.
3. Description of Related Art
For gasoline and diesel fuel powered vehicles, gas tanks are mounted and contain a supply of such fuels. The fuel in gasoline tanks is always contained as both a liquid portion and its vapor phase portion. As ambient air temperature changes, and especially when a fuel tank is heated by incident sunlight, the vapor phase pressure within the tank will rise, and as this occurs, fuel vapor must be released from the tank or the pressure within the tank will quickly reach an unsafe level. Therefore, fuel tank caps have been produced in the prior art to enable fuel vapors to escape from fuel tanks. Such vapor phase outlets, however, present a problem as liquid fuel also tends to exit the fuel tank through the vapor outlet channel, and this causes a fire hazard condition to develop. Furthermore, liquid gasoline and similar fuels are considered to be a health risk and to contaminate the environment. Especially for gasoline fuel tanks on vehicles such as motorcycles and all-terrain vehicles, there is a significant problem with liquid fuel spilling from the fuel tank through outlets designed for vapor phase release. Furthermore, when a motorcycle or similar vehicle falls over or is inverted by accident or for maintenance work, liquid fuel can escape rapidly through vapor release passages. The following abstracts define the present state of this field in contending with these problems.
Gerdes, U.S. Pat. No. 4,036,399: A gas tank cap has an inner part connectable to a gas tank filler pipe and an outer part biased outwardly away from the inner part by a spring and normally freely rotatable relative to the inner part. One or more passages in the cap communicate with the filler pipe and with the ambient atmosphere and have valves interposed in them which are so positioned that when the outer part is pushed towards the inner part the valves are automatically opened to vent pressure from the gas tank. Only after the valves have opened in response to pushing of the outer part towards the inner part do the two parts become coupled for subsequent joint rotation so as to permit removal of the gas cap from the filler pipe.
Crute, U.S. Pat. No. 4,162,021: A pressure-vacuum cap for a chamber such as an automobile gas tank having a normally upwardly extending filler neck formed with a peripherally and radially extending, upwardly facing sealing surface concentric with the longitudinal axis of the neck, the cap comprising a cover, a concentric housing extending downwardly from the cover into the filler neck and a gasket or gaskets providing a seal between the housing and the sealing surface, the housing providing a valve body having a centrally disposed, concentric passageway extending axially therethrough and in communication with the chamber. A pressure-vacuum valve assembly is disposed in that passageway for normalizing the pressure in the chamber, venting the chamber to atmosphere when the pressure in the chamber exceeds a predetermined superatmospheric level and when the pressure in the chamber drops below a predetermined subatmospheric level. The cap also provides, in addition to the pressure-vacuum valve assembly, a roll-over valve assembly. Particularly, a rubber-like insert is disposed in the passageway to provide a downwardly facing, generally conical valve seat, and a ball is disposed in the passageway to move against the valve seat to close the passageway against movement of fluid from the chamber when the filler neck is tilted downwardly to a predetermined angle relative to a horizontal plane. The rubber-like insert also provides a seal against the pressure-vacuum valve assembly.
Harris, U.S. Pat. No. 4,685,584: A fuel cap for closing the filler neck of an off-road vehicle. The fuel cap includes a cover having an opening therethrough and a concentric housing extending downwardly into the filler neck and connected to the cover. A valve body having an upper and a lower chamber disposed therein is fitted into the housing and extends downwardly into the filler neck. The upper chamber and lower chamber have vent openings which cooperate with the opening in the cover to provide a vent path to allow the fuel tank to vent fuel vapor to the atmosphere. The lower chamber includes a floatation ball to seal one of the vent openings in the lower chamber to prevent fuel spillage when the vehicle is subjected to a bump, or is operated on a grade. The upper chamber includes a steel ball which seals one of the vent openings in the upper chamber to prevent fuel spillage when the vehicle is overturned to a substantially vertical position. Interposed between the upper and lower chambers is an upwardly biased plunger which, because of cooperation with the steel ball, extends into the lower chamber to prevent the floatation ball from sealing the vent opening in the lower chamber when the vehicle is in an upright position, and is operated normally. When the vehicle is subjected to a bump, or is operated on a grade, the steel ball rolls off of the upwardly biased plunger which allows the floatation ball to seal the vent opening in the lower chamber to prevent fuel spillage.
Harris, U.S. Pat. No. 4,736,863: A cap for closing the filler neck of a vehicle fuel tank is provided. The cap includes a valve body having an upper opening and movable between a normal lower position and an upper position. The valve body includes a ball disposed therein to seal the upper opening when the cap and filler neck are rolled over to a substantially inverted position and vent openings in the side wall that are located somewhat above the level of the ball when the cap and filler neck are substantially upright. When the valve body is in the normal lower position, fuel vapor is allowed to vent to the atmosphere through the vent openings and upper opening in the valve body. If the ball is upwardly and seals the upper opening prematurely, the fuel vapor will form the valve body to the upper position to allow the fuel vapor to continue to vent to the atmosphere around the valve body. In another embodiment of the invention, the cap may include an axially movable plunger to allow the ball to be manually displaced in the event the ball prematurely seals the upper opening.
Harris, U.S. Pat. No. 4,913,303: A fuel cap includes a float valve assembly for minimizing discharge of liquid fuel splash from the filler neck through the pressure-relief vent passage during normal vehicle operation. The float valve assembly is compatible with a controllable pressure-relief valve in the cap that permits venting of the tank under normal conditions and controls fuel leakage from the cap during a roll-over condition.
Szlaga, U.S. Pat. No. 4,953,583: An apparatus is provided for controlling discharge of fuel vapors from a fuel tank during refueling. The apparatus includes a conduit for conducting fuel vapor between the fuel tank and a first destination such as a vapor treatment canister situated outside of the fuel tank, a valve operable between a flow-blocking position and a flow-delivery position for selectively blocking flow of fuel vapor through the conduit, and a spring for yieldably biasing the valve toward its flow-blocking position. A venting control chamber is situated in communication with the valve for receiving and using fuel vapor pressure from the fuel tank having a magnitude in excess of a predetermined threshold level to exert an opening force on the valve in opposition to the spring so that the valve is moved to its flow-delivery position. Such movement of the valve permits discharge of pressurized fuel vapor in the tank to said first destination through the conduit In addition to the foregoing primary venting system, the apparatus is made stageable by including an optional auxiliary system for venting the fuel tank to a second destination.
Keller, U.S. Pat. No. 5,031,790: A vented fuel tank cap and valve assembly is described having a cam actuated connector for connecting the cap to the top of the filler neck tube for the tank. Three vent passages are employed in the cap with common outlet openings. One passage is normally open but includes a float valve which can close such passage when the vehicle tips.
A second passage includes a pressure relief valve which opens when the tank pressure exceeds a predetermined pressure. The bias spring for the pressure relief valve also functions as the bias for the cam actuated connector. The third passage includes fusible metal inserts provided in the movable pressure relief valve member to open such passage when the temperature of the tank exceeds the melting point of such inserts. The cam actuated connector includes ramp shaped cam surfaces on the outside of the filler neck tube and cam follower pins on the tank cap which move along the ramps and are urged into locking notches by a coil spring which also operates the pressure relief valve.
Bae, U.S. Pat. No. 5,971,203: A vent apparatus of a fuel tank comprising a housing having a through-hole at the bottom communicating with a fuel tank; a valve body mounted on the housing, having a flange, vent slots and a partition wall; a lower cover mounted under the valve body, having a through-hole communicating with the through-hole of the housing and the lower space of the valve body; a ball for opening and closing the through-hole of the partition wall of the valve body, a pushing weight mounted on the upper compartment of the valve body, having a protrusion formed on its bottom to prevent adhesion of the ball to the partition wall of the valve body; and an upper cover positioned on the top of the housing, having a plurality of outlets around its periphery. The amount of the gas vapor to be discharged per unit time in proportion to the pressure of the gas vapor in the fuel tank is controlled to maintain a stable pressure in the fuel tank, and the prevention of fuel leakage via vent apparatus, in case that the automobile is overturned, is effectively enhanced.
Hotch, U.S. Pat. No. 6,648,160: A flush-fitting fuel tank cap 110 is described herein. A flush-fitting tank cap 110 having features and advantages of the present invention is preferably characterized by a cylinder portion 30 adapted such that it may screw into a correspondingly threaded gasoline tank neck or bung 100. The tank cap 110 also preferably includes a handle portion 20 which is preferably mounted in operative relationship to the cylinder portion 30 such that rotation of the handle 20 causes corresponding rotation of the cylinder portion 30. The handle 20 is preferably movable between an up and a down position. A pin 40 is preferably disposed at or near the distal end 22 of the handle portion 20. The handle portion 20 is preferably disposed such that the pin 40 may fit into a slot 50 and a notch 54 formed in the cylinder portion. The pin 40 is preferably free to slide linearly within the slot 50, but the pin 40 preferably rotationally engages within the slot such that the handle portion 20 is restrained from rotational motion relative to the cylinder portion 30 while the handle is in the “up” position as described herein.
Hagano, EP 1 162 099: A fuel cap closes the fuel supply inlet of a filler neck at a narrow operating angle, improving the sealing properties of a gasket. The fuel cap has a cap engagement element which is brought into engagement with the opening engagement element of the filler neck, and seals the gap around the filler neck by means of the gasket. The opening engagement element is formed in an inclined state at a predetermined angle relative to the direction orthogonal to the axial direction for closing the cap. The cap engagement element has a guide surface. This surface is aligned and brought into engagement with the opening engagement element by the rotation of the fuel cap in the closing direction when this element is inserted into the filler neck. The guide surface has a first inclined portion with a considerable inclination angle and a second inclined portion whose inclination angle is smaller.
Our prior art search with abstracts described above teaches: a gas cap with automatic pressure compensation, a pressure vacuum relief fuel tank cap with roll-over safety valve feature, a vented fuel cap with bump and grade seal, a ball-valve fuel cap, a liquid splash control fuel cap, a tank pressure control valve, a quick release vent apparatus for a fuel tank, a vented fuel cap with cam actuated connector, a flush fuel cap, and a tank cap with tank cap apparatus.
However, the prior art does not teach a gas cap valve capable of being retrofitted to most common gas caps and which provides for fuel vapor venting, splash suppression and rollover sealing. The present invention fulfills these needs and provides further related advantages as described in the following summary.